Three-member achromatic microscope objective

ABSTRACT

A three-member microscope objective having a numerical aperture of substantially 0.07 and a magnification of substantially 2.5 X .

uluwu claw 3,598,473

I Inventor Arflwr Shem-hr 501 Field of Search 350/175 EmAu mN-Y- ML.176.2!6. 225 I21 I Appl. No. 20,732 [22] Filed Mar. [8, I970 [56]References Cited l l f S- UNITED STATES PATENTS I731 3,555,234 ll/l967Muller 350/l76 SMMWF' 3,437,398 4/l969 Mulleret al. 550/225 x PrimaryExaminer-John K. Corbin [54] THREE-MEMBER ACHROMATIC MICROSCOPEAttorneys-William C. Nealon, Noble S. Williams and Robert OBJECTIVE J.Bird 2 Claims, 1 Drawing Fig.

521 u.s.c| 350/176,

350/175 ML, 350/2 l 6, 350/225 ABSTRACT: A three-member microscopeobjective having a [5|] lnLCl 002!) 9/12, numerical aperture ofsubstantially 0.07 and a magnification 60215 21/02 of substantially 2.5X.

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* parallel light R8 R7 DZ '14 R2 ITT 1N VENTOR.

ARTHUR H. SHOEMAKER ATTORNEY THREE-MEMBER ACIIROMATIC MICROSCOPE thesuccessive lens elements are designated NDl-NDS. The OBJECTIVE Abbenumbers of the successive lens glasses are designated ulv respectively.BACKGROUND OF THE INVENTION 5 The above-mentioned parameters are relatedto the focal The present invention relates to a microscope objective.length according to the following constructional data:

Refractive I Abbe An object of the present invention is to provide anachro- The foregoing parameters orimflieiuihd space are matic microscopeobjective having a numerical aperture of based on the value of F. Thevalue of F in this case, as an exsubstantially 0.07 and a magnificationof substantially 2.5X, in ample is 73.109 millimeters. Given in numbers,the foregoing which chromatic and spherical aberrations, coma, andastigdata is as follows:

[F=73.109 Magnlfieatlon=2.6X N.A.=0.07]

Radius Thickness Space Refractive Abbe Lens (R) ('I) (S) index NumberSl==9.666 R1=Plano l T1=1.500 ND1=1.78833 III-60A,

S2=-7.363 Rs=14.490 ll T2=2.633 ND2-L80491 0 25.42

R4--l5.32 III T3-l.087 NBS-1.74931 Iii-34.93

$3=12.694 R6=66.418 IV 'I4IL500 NDh-LSMQI r4-25A2 R7=l6.8lli V T5=3.636ND5=L78833 v6=l50.47

R8=l6.ll4

matiam are well corrected while providing a substantially iii? It willbe apparent that the foregoing absolute values are image field when usedwith a telescope objective as described variable depending on the valueof F. Other forms are thus in U.S. Pat. No. 3,355,234 anda typical lOXeyepiece. possible and changes may be made in the values of theconstructional data based on the relationships in the first of theDRAWINQ above charts, without departing from the spirit of this inven-In the drawing, a microscope ob ective IS represented by a on pluralityof lenses viewed transversely to their axis.

What I claim is: DESCRIPTION Ref I. An achromatic microscope objectivehaving a magnifical drawmg, a mlfroscope 3cm: tion of substantially 2.5Xand a numerical aperture of substangenerally shown at 2. It includes afront single lens 4, a doublet any 007 for forming an imagg of an objectplane said image 6, and a doublet 8, all of said lenses being in axialalignment. bein g we corrected for spherical and chromatic aberrations,gg'm fi gfil oblec lo (and coma, astigmatism and curvature of imagefield, said objective .I w n r3 1 8- com risin in axial ali nment:

Lens 4, also designated I, is a negative planoconcavoa g j singlet |ensmember shaped lens. Doublet 6 includes a double convex lens ll and a aSecond doub|e convex lens member 1 double concave lens Ill, togetherforming a negative convexa hi d b| l member Ill; concvo doublet. Double!8 includes a double concave lens second and members forming a negafiyedoublet; and a doublelcosrex lens V, together forming a positive cona fth doub|e.onav lens member w; cavoc n cx 0 6L a fifth double-convex lensmember V;

The lens parameters are as follows: The successive lens radii id f rthand fifth members fonning a positive doublet; are designated ill-R8,where a minus sign indicates radii on the arameters of lens radii(Rl-R8), lens thicknesses centers of curvature lying on the object sideof their vertices. (Th-T5), axial spaces among lens elements and objectThe axial thicknesses of successive lens elements are lane (SI-S3),refractive indices (NDl-NDS), and designated Tl-TS. The successive axialspaces from the ob- Abbe numbers (vl-v5), being determined by thefollowject plane 10 are designated 81-83. The refractive indices of ingrelationship:

Refractive Abbe Lens Radius (R) Thickness 'l') Splice (S) index (ND)Nu(m)ber a fourth double-concave lens member IV;

a fifth double-convex lens member V;

said fourth and fifth members forming a positive doublet;

the parameters of lens radii (RlR8), lens thicknesses (TL-T5), axialspaces among lens elements and object plane (SlS3), refractive indices(NDl-NDS), and Abbe numbers (vi-v5), being determined by the follow- 2.An achromatic microscope objective having a magnification ofsubstantially 2.5)( and a numerical aperture of substantially 0.07 forforming an image of an object plane, said image being Well corrected forspherical and chromatic aberrations, coma. astigmatism and curvature ofimage field, said objective comprising, in axial alignment:

in front planoconcavo singlet lens member I; mg relationship:

[F =73.i09 Magnificatl0n=2.5X NA. =0.07]

Radius Thickness Space Refractive Abbe Lens (R) (T) S) index NumberS1=9.556 R1 Plano I T1=L500 ND1-L78833 11-5047 S2=7.363 R3= 14.490 IIT2=2JS33 ND2-1.80491 v2-25.42

R4 -s.32 III. T3=LOB7 ND3-L74931 vii-34.93

S3=12.li94 R6= 66.418 IV T4==1.600 ND4=L80491 2542 R7 18.816 V T5-3.535ND5-L78833 v6=40. 67

a second double-convex lens member ll; wherein scalar values are givenin millimeters.

a third double-concave lens member I";

1. An achromatic microscope objective having a magnification ofsubstantially 2.5X and a numerical aperture of substantially 0.07 forforming an image of an object plane, said image being well corrected forspherical and chromatic aberrations, coma, astigmatism and curvature ofimage field, said objective comprising, in axial alignment: A FRONTPLANOCONCAVO SINGLET LENS MEMBER I; a second double-convex lens memberII; a third double-concave lens member III; said second and thirdmembers forming a negative doublet; A FOURTH DOUBLE-CONCAVE LENS MEMBERIV; a fifth double-convex lens member V; said fourth and fifth membersforming a positive doublet; THE PARAMETERS OF LENS RADII (R1-R8), lensthicknesses (T1-T5), axial spaces amonG lens elements and object plane(S1-S3), refractive indices (ND1-ND5), and Abbe numbers ( Nu 1- Nu 5),being determined by the following relationship:
 2. An achromaticmicroscope objective having a magnification of substantially 2.5X and anumerical aperture of substantially 0.07 for forming an image of anobject plane, said image being well corrected for spherical andchromatic aberrations, coma, astigmatism and curvature of image field,said objective comprising, in axial alignment: a front planoconcavosinglet lens member I; a second double-convex lens member II; a thirddouble-concave lens member III; said second and third members forming anegative doublet; a fourth double-concave lens member IV; a fifthdouble-convex lens member V; said fourth and fifth members forming apositive doublet; the parameters of lens radii (R1-R8), lens thicknesses(T1-T5), axial spaces among lens elements and object plane (S1-S3),refractive indices (ND1-ND5), and Abbe numbers ( Nu 1- Nu 5), beingdetermined by the following relationship: